Flash lamp and photocell operated bowling pin sensing device



July 14, 1964 J. 5. BOLGER, JR 3,140,872

FLASH LAMP AND PHOTOCELL OPERATED BOWLING PIN SENSING DEVICE 3 Sheets-Sheet 1 Filed March 12, 1962 INVENTOR. Ja /v 6,BOLG!P, J4,

14, 1954 J. G. BOLGER, JR 3,140,872

FLASH LAMP AND PHOTOCELL OPERATED BOWLING PIN SENSING DEVICE 3 Sheets-Sheet 2 Filed March 12, 1962 INVENTOR fa/w 6, 504 an, JP,

United States Patent Ofiice 3,14%,372 Patented July 14, 19%4 3,140,872 FLASH LAMP AND PHQTGCELL OPERATED BQWLING llllN SENSING DEVICE Jenn G. Bother, In, Lafayette, Calih, assignor, by mesne assignments, to Doban Labs, Inc., Sunnyvale, Calif., a corporatien of Calitornia Filed Mar. 12, 1962, Ser. No. 178,873 12 Claims. (Cl. 273-54) This invention relates to apparatus for sensing standing bowling pins and serving as an input means for an electrically operated display board, automatic scorekeeper, or the like; and in particular relates to pin-sensing apparatus suitable for installation in bowling alleys equipped with automatic pinsetting machines, requiring no significant modification of existing conventional pinsetting equipment.

Automatic pinsetting machines are now widely used in bowling, and have contributed to the growing popularity of the game. It has been realized that further increases in enjoyment and popularity may be achieved by the provision of display boards, which would make the number and positions of standing pins more evident to players and spectators, automaitc scoring equipment to compute and display individual and team scores, and the like. However, prior proposals along these lines have not been altogether satisfactory from a practical viewpoint, one difficulty being lack of satisfactory input apparatus for sensing the standing pins. For example, it has been proposed that standing pins be detected by switches attached to the vertically moving portion of a conventional pinsetting machine, in such a way that when this portion of the machine moves down after a ball is rolled, the heads of any pins that remain standing actuate certain of the switches to signal the number and positions of the standing pins. A practical disadvantage of this prior proposal is that it is not consistent with normal operation of the pinsetting machines, in which the vertically moving portion comes down after the first ball in a frame is rolled, but not after the second ball in a frame is rolled. Hence, the proposal to use switches in the machine for detecting standing pins cannot detect the pins remaining standing after the second ball of the frame, unless the operation of the machine is modified, which not only would involve an additional expense, but also would slow down operating of the pinsetting machine and thus slow down the game.

Among the objects of this invention are to provide an improved bowling pin sensing device that will sense the number and positions of the pins that remain standing after each ball is rolled; to provide such a device that may be installed in bowling alleys equipped with conventional pinsetting machines without any significant modification of the existing equipment, as to either structure or operation; and to provide such a device suitable as an input means for display boards, automatic scorekeeping apparatus, and the like.

Briefly, in accordance with this invention, a bowling pin sensing device comprises a plurality of flash lamps and a plurality of photosensors, arranged in an optical system such that the head of each standing bowling pin reflects light from one of the lamps to one of the photosensors, and such that a unique combination of a particular lamp and a particular photosensor is provided for each pin position. Preferably, there are four lamps and associated lenses arranged to form four beams of light, one beam illuminating the heads of the four pins arranged along one side of the triangle in the usual triangular pattern in which the pins are set, another beam illuminating the heads of the three pins in the next line parallel to the line of pins illuminated by the first beam, a third beam illuminating the heads of the two pins in the next parallel line, and the fourth beam illuminating the head of the remaining pin. Four photosensors are arranged with associated lenses in such a Way that they receive light only from four zones of substantially similar configuration to the four light beams, and such that one photosensor receives light reflected from the heads of the four pins arranged along another side of the triangle, at an angle to the beams of light from the four lamps such that each of these four pins is illuminated by a different one of the four lamps. Another photosensor receives light reflected from the heads of the three pins in the next line, illuminated by three different lamps; a third photosensor receives light reflected by the heads of the two pins in the next line, illuminated by two different lamps; and the fourth photosensor receives light reflected from the head of the remaining pin. Thus, for each pin there is provided a unique combination of a particular lamp and a particular photosensor. After each ball is rolled, and enough time has elapsed for the pins to come to rest, the four lamps are flashed on sequentially and the four photosensors provide electric signals that identify the number and positions of the standing pins.

The foregoing and other aspects of this invention may be better understood from the following illustrative description and the accompanying drawings.

FIG. 1 of the drawings is a plan view of a portion of a bowling lane, showing ten bowling pins set up in the usual triangular pattern, and showing, in section and somewhat schematically, parts of a sensing device embodying the principles of this invention, this section being taken in a horizontal plane indicated by the line 1-1 of FIG. 2.

FIG. 2 is an elevation taken on a vertical plane just behind the back row of bowling pins, as indicated by line 2-2 in FIG. 1.

FIG. 3 is a horizontal section taken along the line 33 of FIG. 2.

FIG. 4 is an electrical circuit diagram of the pin sensing device operating a display board which indicates the number and position of standing pins.

Referring to FIGS. 1, 2, and 3, ten bowling pins, set up in the usual triangular pattern, are identified by reference numbers 1 through 10. The pins are illustrated in their initial positions. After a ball has been rolled, some of the pins may be displaced to some extent away from these initial positions and this fact must be taken into consideration in the design of a pin sensing device. Broken lines 11 through 20 define the areas within which the heads of the pins may be displaced after the first ball is rolled, and still have the standing pins accepted by a conventional pinsetting macihne of a type now in wide use. The pin sensing apparatus should not be adversely affected by pin displacements of this magnitude. Reference number 21 identifies the alley or lane in which the pins are set; numbers 22 and 2?: identify the conventional gutters on each side of the lane, and number 24 identifies a conventional screen disposed in front of the pinsetting machinery for the purpose of concealing this machinery from the view of players and spectators.

The lamp and photosensor assemblies provided in accordance with this invention are preferably placed on opposite sides of lane 21, just behind the screen 24. Thus, they are scarcely, if at all, noticeable, and in no way interfere with either the game or the conventional pinsetting macihnery. In a preferred embodiment, a horizontal bar 25 extends across the width of the lane, and supported therefrom are two housings 26 and 27, one of which contains the flash lamps and their lenses, and the other of which contains the photosensors and their lenses. The housing containing the lamps may be upon either side of the alley, and the housing containing the photosensors is on the other side.

The four flash lamps are identified by reference numbers 28, 29, 30, and 31. Although the type of lamp used is not critical, small gas-discharge lamps of a type used in high speed photography, and sometimes called electronic flash or strobe lamps, give exceptionally good results. The light from each flash lamp is focused into a well defined beam of a particular cross section by means typically comprising a mask and a lens. Thus, adjacent to lamp 28 there is a mask 32, generally made of metal or other opaque material, and having a small aperture through which light can pass to define the shape of the desired light beam. The light passing through the aperture of mask 32 is focused by a lens 36 into a beam of almost collimated, slightly diverging light rays. For reference, this beam is herein identified as beam I.

The boundaries of beam I are marked by broken lines 60 and 61 in FIG. 1, and by broken-line trapezoid numbered 76 in FIG. 2. Reference number 40 identifies the opening through which beam I emerges from housing 26. It will be noted that this beam illuminates the heads of pins 1, 2, 4, and 7, Which are arranged in a line along one side of the triangular pattern in which the pins are set. From FIG. 2 it will be noticed that the housing 26 is above the tops of the pins, and that the beam slants downward from opening 40 across the heads of the pins, having the cross section indicated by broken-line trapezoid 76 at the vertical plane represented by line 2-2 in FIG. 1. This insures that the head of each pin will be illuminated, and that no pin can have its head shadowed by a pin in front of it, regardless of how the pins may be displaced from their initial positions. It will also be noted from FIG. 2 that beam I is wider at the bottom than at the top. The reason for this will become apparent from a careful examination of FIG. 1, remembering that the beam slants downward onto the heads of the pins, and that pin 1 must be illuminated even though it may be displaced to any position within the broken line 11. The top of the beam, which is used to illuminate the head of pin 7, can be narrower than the bottom of the beam, and still illuminate the head of this pin at any position which it may have Within the broken line 17. It is desirable that the beams be no larger than required-larger beams would serve no useful purpose, and would have the disadvantage, among others of increasing light reflected by objects other than the heads of standing pins, which would increase the possibility of false signals.

In a similar manner, masks 33, 34, and 35. lenses 37, 38, and 39, and openings 41, 42, and 43 are provided in association with lamps 29, 3t], and 31, to forms beams II, III. and IV. The edges of beam II are defined in FIG. 1 by broken lines 62 and 63, and in FIG. 2 by broken-line rectangle 77; the edges of beam III are defined in FIG. 1 by broken lines 64 and 65, and in FIG. 2 by broken-line rectangle 78; and the edges of beam IV are defined in FIG. 1 by broken lines 66 and 67, and in FIG. 2 by broken-line rectangle 79. It will be noted that the cross sections of the beams in the plane of the line 22 decrease progressively from beam I to beam IV, beam I, which illuminates four pins, having the largest cross section, and beam IV, which illuminates only one pin, having the smallest cross section. This is a consequence of each beam being formed with a cross section no larger than is required to illuminate the heads of the desired pins throughout the expected range of their respective positions, indicated by the broken lines 11 through 20. As has already been mentioned, this limitation in the size of the beams is important for reducing stray light reflected from objects other than the heads of pins. It is also important for another reason, which will be discussed later on in this specification.

The cross section of each beam is primarily determined by the size and shape of the aperture in the mask associated with that beam. The lenses may advantageously be designed to produce an image of this aperture approximately in the vicinity of the plane identified by line 22 of FIG. 1, although the exact position of the image is not critical, inasmuch as the edges of the beams remain reasonably sharp over a considerable distance of the beam lengths. It will also be noticed that the lamp, mask and lens for producing beam 1V lie beneath the lamp, mask and lens for producing beam III. This permits optimum placement of the lamps, masks, and lenses for forming the desired beam patterns while keeping the overall Width of the apparatus sulficiently small for installation in conventional bowling lanes without significant modification of existing structures.

The optical systems within housings 26 and 27 are essentially the same, except that where one has flash lamps, the other has photosensors. The four photosensors are identified by reference numbers 44, 45, 46 and 47; the four masks by reference numbers 48. 49, 5t), and 51; the four lenses by reference numbers 52, 53, 54, and 55; and the four openings in the housing by reference numbers 56, 57, 58 and 59. The photosensors are responsive only to light originating within the beam-like zones, which occupy exactly the same positions that would be occupied by light beams if the photosensors were replaced by lamps. Thus, photosensor 44 responds only to light reflected from objects within zone A, the boundaries of which are indicated in FIG. 1 by broken lines 68 and 69, and in FIG. 2 by broken-line trapezoid 80; photosensor 45 responds only to light reflected from objects within zone B, the boundaries of which are indicated in FIG. 1 by broken lines 70 and 71, and in FIG. 2 by broken-line rectangle 81; photosensor 46 responds only to light reflected from objects Within zone C, the boundaries of which are indicated in FIG. 1 by broken lines 72 and 73, and in FIG. 2 by broken-line rectangle 82; and photosensor 47 responds only to light reflected from objects within zone D, the boundaries of which are indicated in FIG. 1 by broken lines 74 and 75, and in FIG. 2 by broken-line rectangle 83. It will be noted that zones A, B, C, and D are of the same size and shape as light beams I, II, III, and IV, respectively, but cross the light beams at an angle such that the intersection of each zone with a light beam covers only one pin position. The four photosensors 44 to 47 may be any type of transducer that converts flashes of light into electric pulses; for example, phototubes, semiconductor photoelectric or photoconductive cells, and the like. Because of low cost and reliability, cadmium sulfide cells may be employed advantageously. Although the speed of response of cadmium sulfide cells is generally considered to be low, it has been found that such cells will operate at quite high speeds, and hence be suitable for the present use, when brilliant, high-speed flashes of light are provided by the use of strobe-type photographic flash lamps for the lamps 28 to 31.

The optical system described responds only to reflecting objects lying Within the volumes defined by the intersections of beams I, II, III, and IV with the zones A, B, C, and D. Thus, referring to FIG. 2, it will be noted that beam I has a rather large cross section in the vicinity of the last row of pins, and may illuminate pins that are not standing in an upright position. Nevertheless, the photosensors will respond only to light reflected from objects within one of the zones A, B, C, or D. Hence, in the vicinity of the back row of pins, that portion of beam I (having a cross section defined by broken-line trapezoid 76) that does not overlap zone D (having a cross section defined by broken-line rectangle 83) is not effective to produce a response at the photosensor 47. Thus, the photosensors respond only to light reflected from the heads of standing pins.

It is also important to note that the sensing system described is not affected by steady illumination of the bowling lane and the pins in the usual manner. Such illumination, of course, causes some light to reach the photosensors, and may cause the flow of a small, relatively continuous electric current through the photosensors. The brilliant flashes of light that are reflected from the heads of standing pins when the flash lamps are fired cause sud- Q) den increases in the light reaching one or more photosensors, and thus produce appreciable electric pulses superimposed upon the smaller steady-state electric currents. It is the electric pulses, and not the steady-state currents, that are utilzed as input signals to subsequent apparatus.

FIG. 4 is a schematic, electrical circuit diagram of a sensing device embodying principles of this invention, connected to a display board indicating the numbers and positions of the pins that are still standing after each ball has been rolled. it will be appreciated that the display board is but one example of a use for the pin sensing device herein described; another possible use is as the input device for automatic score computing and registering equipment.

The display board may comprise ten electric lamps, identified by reference numbers 101 through 11%, arranged in a triangular pattern corresponding to the pattern in which bowling pins are normally set. These lamps are controlled by ten relays, identified by reference numbers 111 through 120, a normally open contact of relay 111 being connected in series with lamp 101, a normally open contact of relay 112 being connected in series with lamp 102, etc., so that each lamp is lit when the associated relay is energized to close its contacts, and is extinguished when the relay is de-energized and the relay contact opens. Each relay has its windings connected in series with its own contact, in such a way that the same contact that lights the lamp also acts as a holding contact for the relay to keep it energized until the circuit is broken, as hereinafter described. Any suitable power source for operating the lamps and relays may be provided, as indicated by the terminal 142.

A six-position stepping switch driven by stepping motor 121 has six switch decks 122, 123, 124, 125, 126, and 127. It will be clear to those skilled in the art that electronic switching circuits may be substituted for the mechanical switch shown, if desired, without changing the essential principles involved. The six switch arms, one per deck, are shown at their initial or zero positions, from which each operating cycle starts. As is hereinafter explained more fully, after each ball is rolled, the stepping motor 121 rotates the six switch arms one complete revolution clockwise, returning them to the zero position shown. Operation of the stepping motor is initiated by closing any one of three parallel switches 129, 131 and 131, which connect one terminal of the stepping motor to ground through a normally closed contact of a relay hereinafter described. The other terminal of the stepping motor is connected to any suitable source of electric power, schematically represented by terminal 12%.

The three switches 129, 130 and 131, which initiate operation of the stepping motor 121, may be, respectively, a manually-operated switch 129, whereby operation of the stepping motor can be initiated whenever desired by a player or other person, a switch 130 attached to the automatic pinsetting machine in such a way that this switch is automatically closed when the vertically movable portion of the pinsetting machine begins to move down toward the pins after the first ball of a frame is rolled, and a switch 131 attached to the pinsetting machine in such a way that switch 131 is closed when the arm of the pinsetitng machine that sweeps the remaining pins off the alley begins to move after the second ball is rolled. Switches 130 and 131 are ordinary types of small electric switch s, which may easily be attached to the pinsetting machine without significant modification of the machine. They serve the purpose of starting an automatic operation of the bowling pin sensing cycle in sufficient time for esnsing to be completed before the pinsetting machine removes the pins, and yet with sufficient delay after the ball is rolled (this delay being inherent in the pinsetting machine itself) that the sensing cycle does not start until moving pins have had time to come to rest.

Once a sensing cycle has been started by closing switch 12.9, 130, or 131 sufficiently long for the stepping motor 121 to move the stepping switch arms one step clockwise from their initial or zero positions to their step 1 positions, the circuit from the stepping motor to ground is kept closed through switch deck 12-2, whereby the stepping motor 121 continues to operate until the six switch arms have been moved through one complete revolution and returned to the zero position, irrespective of whether or not the switches 129, 130, and 131 remain closed. At the end of one complete revolution, the circuit to ground through switch deck 122 is broken for stopping the stepping motor, and thus terminating the sensing cycle. However, it may occur that one of the switches 12.9, 130, and 131 is still closed at this time, and therefore means must be provided to inhibit the immediate restarting of a new cycle. This is accomplished by the relay 143, which, when energized by the closing of any of the switches 129, 1319, and 131, opens the normally closed relay contact in series with these switches, thus breaking the circuit and keeping it broken until relay 143 becomes de-energized by a later opening of the starting switch. Thus, each operation of any of the switches 12), 130, and 131 closes the circuit only during a time interval suflicient for the operation of relay 143, the delay in operation of relay 143 being made sufiicient to start stepping motor 121 and cause it to move the stepping switch arms at least one step clockwise. The necessary delay may be obtained either by choice of an appropriate relay having a delayed action characteristic, or by the addition of other circuitry to produce a delay, such as the capacitor 144 connected in parallel with the winding of relay 143, both being connected through resistor 145 to the electrical power supply represented by terminal 146. Since sufiicient current to operate relay 143 cannot flow through its winding until capacitor 144 has charged through resistor 145, a circuit of this type can be designed to provide sufi'h cient delay to allow stepping motor 121 to start.

Switch deck 123 has a switch arm connected to a power supply represented by terminal 132, appropriate for operation or" the four flash lamps 28, 29, 30, and 31. These four lamps are connected to the second, third, fourth and fifth step positions of switch deck 123, whereby the four lamps flash on in sequence during each cycle of steppingswitch operation.

Photosensors 44, 45, 46, and 4-7 are connected to an appropriate electrical supply represented by terminal 133. Load resistors 13 i. 135, 136, and 137 are provided in series with the four photosensors, as shown. Each flash of light received by one of the photosensors causes a pulse of increased current to flow through it, and a pulse of voltage to appear across its load resistor. These pulses preferably are amplified by amplifiers 138, 139, 140, and 141, or reformed by trigger circuits or the like, of any type suitable to insure that pulses of sufiicient amplitude and duration for the reliable operation of relays will be obtained.

The output of amplifier 141 leads directly to the winding of relay 117, so that each flash of light received by photosensor 47 causes relay 117 to close, thereby lighting lamp 1th? which indicates that bowling pin 7 is standing. This operation is consistent with the optical system shown in FIGS. 1 and 2, whereby the only flashes of light received by photosensor 4-7 are those reflected from the head of pin 7 when lamp 28 lights.

The output of amplifier leads to the switch arm of deck 124. Step 2 of this deck is connected to the wind ing of relay 114, which lights lamp 104, representing pin 4; and step 3 of the same deck is connected to the wind ing of relay 118 which lights lamp 1%, representing pin 8. This again produces the desired result: at step 2 in the cycle lamp 28 flashes, and if pin 4 is standing, a flash of light is reflected to photosensor 46, thereby energizing relay 114 and lighting lamp 104. At step 3 of the cycle, lamp 2.9 flashes, and if pin 8 is standing, light is reflected to photosensor 46, relay 118 is energized, and lamp 1&8 becomes lit.

The output of amplifier 239 is connected to the switch arm of deck 125, from the second step of which there is a connection to relay 112 for lighting lamp 132 representing pin 2, from the third step of which there is a connection to relay 115 for lighting lamp 105 representing pin 5, and from the fourth step or" which there is a connection to relay 119 for lighting lamp 1&9 representing pin 9. Thus, it is apparent that lamp 1G2 will be lit when pin 2 is standing, lamp 105 will be lit when pin 5 is standing, and lamp 109 will be lit when pin 9 is standing. The output of amlifier 138 connects to the switch arm of deci: 126, having a connection from its second step position to relay 111 for lighting lamp 1M representing pin 1, from its third step position to relay 113 for lighting lamp 193 representing pin 3, from is fourth step position to relay 116 for lighting lamp representing pin 6, and from its fifth step position to relay 126 for lighting lamp 116 representing pin It). Hence, lamp 161 is lit when pin 1 is standing, lamp 183 is lit when pin 3 is standing, lamp 106 is lit when pin 6 is standing. and lamp 110 is lit when pin 10 is standing.

The circuits for energizing the ten relays 111 through 120 are completed to ground through deck 127 of the stepping switch, at all switch positions except step 1 of the sensing cycle. Thus, at the very beginning of each cycle. when the stepping motor moves the six switch arms to step 1, the ten relays are de-energized and all ten of the lamps I01 to 110 are extinguished. At step 2, the circuits from the relays to ground are closed again through deck 127, whereupon, as the four flash lamps 23 to 31 flash on in sequence at steps 2 through 5, and light is reflected to the various ones of the photosensors 4-4 to 47 from the heads of standing pins, the proper ones of lamps 101 to 110 are lit to represent the number and positions of the standing pins. It is apparent that the circuits of relays Ill to 129 are so arranged that, when a relay is energized, it is held in the energized state until the circuit through switch deck 127 is broken at the beginning of the next cycle. Thus, the display board always shows which pins were left standing after the last ball was rolled, even though the pins may subsequently be swept away or reset. The display is automatically cleared just in time to receive the input data from the next cycle.

In its broader aspects, this invention is not limited to the specific embodiment illustrated and escribed. Various changes and modifications may be made without departing from the inventive principles herein disclose What is claimed is:

l. Apparatus for sensing the bowling pins remaining standing in a bowling lane after a ball is rolled, such apparatus comprising:

(a) two housings located on opposite sides of the lane in front of the place where the pins are customarily set;

(/1) four flash lamps within one of said housings;

(c) means for flashing said lamps in sequence after the rolling of each ball;

(z!) a plurality of lenses and mashing means in the housing with said lamps and arranged to form th light therefrom into four beams, one beam directed at an angle down and across the bowling lane along a line of four positions in which bowling pins are set so that light from said beam is reflected off the heads of each of the four pins when same are left standing, another beam directed along the parallel line of three positions in which bowling pins are set so that light from said beam is reflected oil the heads of each of three pins when same are left standing, another beam directed along the parallel line of two positions in which bowling pins are set so that light from said cam is reflected oil the heads of each of the two pins when same are left standing, and the last beam directed at the remaining position is which a boWJing pin is set so that light from said beam is reflected oil the head of the remaining standing;

(6) four transducers within the other of said housings and operable to convert flashes of light to electric pulses; and

(f) a plurality of lenses and masking means within the housing with said transducers and arranged for (1) directing to one of said transducers the light flashes reflected from the heads of pins in a zone extending along a line of four pin positions, (2) directing to another of said transducers the light flashes from the heads of pins in a zone extending along the parallel line of three pin positions, (3) directing to another of said transducers the light flashes reflected from the heads of pins in a zone extending along the parallel line of two pin positions, and (4) directing to the last of said transducers the light flashes reflected from the head of the pin in a zone extending to the remaining pin position, such zones extending at an angle to and intersecting said light beams whereby the number of the reflected light flashes directed to all said transducers and thereby converted to the same number of electric pulses is the number of pins remaining standing after a ball is rolled.

2. Apparatus as defined in claim 1, the lamps and transducers being disposed above the bowling lane higher than the heads of the standing bowling pins, the intersecting light beams and zones slanting downward onto the heads of the standing pins, whereby no standing pin can have the light passing from a lamp to its head and from its head to a transducer blocked by another standing pin.

3. Apparatus as defined in claim 2, the lamp having a beam directed to a single pin position being below the lamp having a beam extending along a line of two pin positions, and the transducer receiving light reflected from a single pin position being below the transducer receiving light from a line of two pin positions.

4. Apparatus as defined in claim 1, the width of each beam being suilicient to illuminate the heads of the standing pins in its line of positions, but not to illuminate the heads of pins in other lines sufliciently for the reflection of light therefrom to the transducers, irrespective of displacements of the heads of the pins within the areas of acceptance by conventional pin-setting machines.

5. Apparatus as defined in claim 4, the four beams having different cross sections at a vertical plane behind the back row of bowling pin positions, the beam directed along a line of four pin positions having the largest cross section, and the beam directed to a single pin position having the smallest cross section.

6. Apparatus as defined in claim 5, the largest tion being trapezoidal, larger at the bottom than at the top, and the other cross sections being rectangular.

7. Apparatus as defined in claim 6, the four zones having cross sections similar to those of the four beams, the zone extending along a line of four pin positions having the largest cross section, and the zone extending to a single pin position having the smallest cross section.

8. Apparatus for sensing standing bowling pins comprising (a) means for forming a plurality of light beams in time sequence, each light beam being directed to illuminate standing ones of a distinct group of bowling pins, the number of such groups being less than the largest number of pins which can possibly be stand- (b) a plurality of light sensitive devices each arranged to receive light reflected from standing ones of a distinct series of said bowling pins, the number of said series being less than the largest number of pins which can possibly be standing, each pin in one of said series being in a different one of said groups,

(c) indicator means representative of each bowling pin responsive to operation of said light sensitive devices, and

pin when same is let" (d) means operable in time coincidence with said light beam forming means to connect a light sensitive device to the indicator for the bowling pin of that group being illuminated in the series from which it is adapted to receive light.

9. Apparatus for sensing standing bowling pins comprising (a) a plurality of light sources each arranged to project a light beam to illuminate standing ones of a distinct group of bowling pins, the number of such groups being less than the largest number of pins which can possibly be standing,

(b) a plurality of lght sensitive transducers each arranged to receive light reflected from standing ones of a distinct series of said bowling pins, the number of said series being less than the largest number of pins which can possibly be standing, each pin in one of said series being in a different one of said groups,

(c) a plurality of signal-responsive devices each representative of one of said bowling pins,

(d) means operable to actuate said light sources in time sequence, and

(6) means operative in timed relation to the light-source actuating means for connecting each light sensitive transducer to each of said devices representing a bowling pin in the series thereof while such pin is in the group being illuminated.

10. Apparatus for sensing bowling pins, initially set in the customary triangular pattern of ten pin positions, remaining standing after a ball is rolled, such apparatus comprising:

(a) means for forming four beams of light, one beam directed along a line of four pin positions so that light from said one beam is reflected oh the heads of each of the four pins when same are standing, another beam directed along the parallel line of three pin positions so that light from said beam is reflected ofl the heads of each of the three pins when same are standing, another beam directed along the parallel line of two pin positions so that light from said beam is reflected oil? the heads of each of the two pins when same are standing, and the last beam directed to the remaining pin position so that light from said beam is reflected off the head of the remaining pin when same is standing;

(b) means for automatically flashing said four light beams sequentially to produce four sequential flashes of light after each ball is rolled;

(c) four sensing means repsonsive to the light reflected from the heads of said pins, one of said sensing means responsive to light flashes reflected from the heads of pins in a zone extending along a line of four pin positions, another of said sensing means responsive to light flashes reflected from the heads of pins in a zone extending along the parallel line of three pin positions, another of said sensing means responsive to light flashes reflected from the heads of pins in a zone extending along the parallel line of two pin positions, and the last of said sensing means responsive to light flashes reflected from the head of the pin in a zone extending to the remaining pin position, such zones extending at an angle to and intersecting said light beams, whereby the number of the reflected light flashes sensed by all said sensing means is the number of pins remaining standing after a ball is rolled.

11. Apparatus for sensing bowling pins, initially set in the customary triangular pattern of ten pin positions, re-

maining standing after a ball is rolled, such apparatus comprising:

(a) four flash lamps;

(b) means for automatically lighting in sequence after each ball is rolled;

(c) means for forming the light from each of said four lamps into a separate beam, and for directing one beam along a line of four pin positions so that light is reflected oil the heads of each of the four pins when same are standing, another beam along the parallel line of three pin positions so that light is reflected off the heads of each of the three pins when same are standing, another beam along the parallel line of two pin positions so that light is reflected oil the heads of each of the two pins when same are standing, and the last beam to the remaining pin position so that light is reflected off the head of the remaining pin when same is standing;

(d) four photosensors operable to produce electric pulses in response to flashes of light reflected from the heads of said pins, one of said photosensors responsive to light flashes reflected from the heads of pins in a zone extending along a line of four pin positions, another of said photosensors responsive to light flashes reflected from the heads of pins in a zone extending along the parallel line of three pin positions, another of said photosensors responsive to light flashes reflected from the heads of pins in a zone extending along the parallel line of two pin positions, and the last of said photosensors responsive to light flashes reflected from the head of the pin in a zone extending to the remaining pin position, such zones extending at an angle to and intersecting said light beams, whereby the number of reflected light flashes sensed by all said photosensors is the number of pins remaining standing after a ball is rolled.

12. Apparatus for sensing standing bowling pins comsaid four lamps prising:

(a) means for illuminating the heads of standing ones of a plurality of distinct groups of bowling pins, one group after the next, thereby illuminating all the pins of one group while leaving the remainder dark, the sum of the pins in all such groups comprising all of the pins possibly remaining standing approximately in the position in which they are customarily set, whereby light is reflected from the heads of each such standing pins,

(b) a plurality of light sensitive devices each arranged to receive light reflected from the heads of any standing ones of a series of bowling pins, one such series being distinct to each such device, wherein at least some of said series have more than one pin and no two pins in any one of said series are from the same one of said groups, and

(c) standing pin indicating means responsive to said light sensitive devices.

References Cited in the file of this patent UNITED STATES PATENTS 2,014,306 Barker Sept. 10, 1935 2,319,925 Flanagan May 25, 1943 2,613,933 Johns et al. Oct. 14, 1952 2,980,424 Sanders et al Apr. 18, 1961 FOREIGN PATENTS 306,671 Switzerland July 1, 1955 

12. APPARATUS FOR SENSING STANDING BOWLING PINS COMPRISING: (A) MEANS FOR ILLUMINATING THE HEADS OF STANDING ONES OF A PLURALITY OF DISTINCT GROUPS OF BOWLING PINS, ONE GROUP AFTER THE NEXT, THEREBY ILLUMINATING ALL THE PINS OF ONE GROUP WHILE LEAVING THE REMAINDER DARK, THE SUM OF THE PINS IN ALL SUCH GROUPS COMPRISING ALL OF THE PINS POSSIBLY REMAINING STANDING APPROXIMATELY IN THE POSITION IN WHICH THEY ARE CUSTOMARILY SET, WHEREBY LIGHT IS REFLECTED FROM THE HEADS OF EACH SUCH STANDING PINS, 